IntegerName[10^16-1,{"Approximate"}]

IntegerName[10^16-1,{"ApproximateWords"}]

IntegerName[10^13-1,{"Japanese","Approximate"}]
IntegerName[10^13-1,{"Japanese","ApproximateWords"}]

Options[IntegerName]

?IntegerName

"foo `this``is` bar `someMathExpression``4`"

MatchQ[$AlphaOutputLanguagex,_Symbol]